Expert: James Yee - 12/1/2011

Question
QUESTION: I have 2 humidors and use the same water and same foam type humidicant in both. The first one has never had mold it's at 78% humidity.

In the second box suddenly there is green mold growing on the foam humidicant at 67% humidity.

I wiped down the affected humidor with grain alcohol, replaced the humidicant with sterile moistened cotton.

Here is the problem: every 3 days tiny spots of mold appear on the cotton, so I discard it and start over (it has not yet affacted any cigars).

Why am I having mold in one box and not the other?
How do I get rid of it?

ANSWER: Hi Bill,

Without visually inspecting your humidor, I can't be sure what the exact cause of the mold growth is but here are some things you can try:

If you are using analog hygrometers, you should salt test them and make sure they're still accurate.  Analog hygrometers can sometimes lose accuracy over time and give a false reading. (Even though the hygrometer displays a humidity level of 67%, it could be much higher.)  The slightest jolt to your humidor or even regular humidor use (ie: repeated opening and closing the humidor lid) can eventually move the hygrometer needle out of sync so it's important that you test and calibrate your hygrometers at least once a year.

If you are using digital hygrometers, test and replace the batteries if necessary.  Sometimes old, weak and depleted batteries can give off an incorrect reading.  Digital hygrometers are normally factory calibrated and extremely accurate but depending on the brand and model, they may require additional programming to function properly.  Check if your digital hygrometers require this.

If your hygrometers are working properly, the next thing you should check is the placement of the humidicant.  If the humidifier is placed in an obstructed location inside your humidor (such as directly underneath a tray or shelf or in a crowded corner) or the humidifier is obstructed by your cigars, this can cause excess moisture to build up on the humidifier which will lead to mold growth.  Keep the humidifiers and hygrometers clear of any obstructions to ensure that humidity will circulate properly.  

Mold can also appear from bacteria contamination.  If your hygrometers are properly calibrated and your humidifiers are not obstructed in any way but mold spots continue to appear, your foam element may be contaminated so try using another type of humidifier.  Humidor crystals & beads are made from a cellulose polymer which is less susceptible to bacteria growth so you may want to try using these.

I hope this helps!  If you have any more questions, please feel free to just ask and I will be happy to help.

Regards,
James

---------- FOLLOW-UP ----------

QUESTION: Thanks for your time and interest in this. You have given me a some great tips that I did not know. However, it is not yet the solution.

I do use and salt test analog hygrometers, but more importantly I can tell the humidity level by the feel of my cigars. The cigars in the affected humidor are bordering on too dry 67%, so I know moisture is not the problem. I did not know that digitals are more accurate, I would like to get a few.

One humidifier is secluded, the other is not (both get mold at the same rate). And they dry out rapidly (4 days). So this is a possible but unlikely issue. (I have moved them as you suggest).

I even tried using new ultra purified water. Both humidors: have a mix of the same lots of cigars, boxes are of same quality (mid-range) spanish cedar construction, same location, opened and closed weekly.

My understanding about mold is that it is present dormant most everywhere, and becomes active in the presence of moisture. I wish I knew more about the science behind it because I am totally stumped here. I guess I will go through the entire clean/disinfectant process again, but I have a gut feeling that it will not help. Then I suppose I will have to discard a $150. box.

Any additional insight would be greatly appreciated. What brand/model digital hygrometer do you use?

Thanks once again for you help.

ANSWER: Hi Bill,

100% distilled water usually works great but I find that double-distilled water (aka bidest water) works even better.  You can usually buy this at any specialty store that sells distilled water and water filtration supplies.  Bidest water is also used in lab work so you can also find it at most chemistry/science-supply shops.  (If not, I'm sure they can order it for you.)

You're right, mold is formed from microscopic bacteria and is usually dormant.  When coupled with just the right amount of moisture and temperature, the bacteria will turn into a fungal growth that spreads quickly.  Cigar mold is the same type of fungal growth that you would find on spoiled food.  (If you look at cigar mold under a microscope, you will notice that it looks like tiny mushrooms.  A cigar mold spore will have a long tubular body and a mushroom cap-like head.)

Mold can also form from a dirty or sweaty fingerprint so before handling your cigars, be sure to thoroughly wash and dry your hands.

I use a variety of digital hygrometers.  For my desktop humidors, I prefer Caliber, Xikar and Madelaines which are all very good.  For larger humidors/cabinets, my electronic humidifers have built-in digital hygrometers but I will also use Caliber and Xikar as a backup hygrometer.

If your foam humidifiers are drying out within 4 days, I would suggest re-seasoning your humidors and switching to humidor crystals or beads.  They're less susceptible to bacteria plus they absorb and regulate moisture much better and longer than the traditional foam element so you'll find that they perform longer before requiring refills.

I hope this helps!  As always, if you have any more questions, please feel free to just ask.

Regards,
James

---------- FOLLOW-UP ----------

QUESTION: At your suggestion I am going to try beads. But this opens up a can of worms, as I have spent countless hours on the web trying to figure out how:

There are:

1. Low density silica gel ie.  RH 50% cat litter, or other brands (If it is RH50 how does it keep RH at 70%)?

2. Heartfelt beads 60%,65,70% (High density silica gel with lithium chloride)

3. HCMcigarbeads .com clay beads.

4. Boveda salt solution (Can I just use salt like salt test permanently)?

5. SAP Super Absorbent Polymer (what is this)?

Which if any do you recommend?

Thanks again.

Answer
Hi Bill,

I would recommend Heartfelt 70% beads.  I use these and they work great.  A lot of people that contact me here on allexperts also find heartfelt to be very reliable.

Cat litter is used as a regulator to balance the humidity if there's too much humidity in your humidor.  Cat litter is often used in addition to genuine humidor beads or if the humidor naturally has high humidity (such as after being seasoned.)  Even though it does work, I'm not a big fan of putting cat litter in my humidor.

Super Absorbent Polymer is the same as humidor gel.  It's basically a white powder that expands to a slush-like paste when distilled water is added.  Cigar pillows use SAP.

Regards,
James